Suarez on just war
Religion & Liberty Online

Suarez on just war

A few years ago I asked the question: “Just how many unjust acts can a just war encompass before it ceases to be a just war?” This question assumed the connection between what scholars have defined as a distinction between ius ad bello and ius ad bellum, justness in the occasion for or cause of war and justness in the prosecution of war.

Prof. Stephen Bainbridge and Prof. Anthony Clark Arend were among those kind enough to respond, alluding to this classical distinction.

I just came across this definition of just war from the sixteenth-century Jesuit doctor Francisco Suarez:

In order that a war may be justly waged, certain conditions must be observed and these may be brought under three heads. First it must be waged by a legitimate power. Secondly its cause must be just and right. Thirdly just methods should be used, that is equity in the beginning of war, in the prosecution of it, and in victory (Tractatus de legibus, I, 9).

With Suarez’s definition in mind, I think we can summarize the matter thusly:

There is an important classical and scholastic distinction between ius ad bellum and ius ad bello, corresponding to the second and third heads of Suarez’s definition respectively. We might therefore say that a war can be just in a divided sense in two distinct ways: in its cause and in its execution. In this divided sense then Bainbridge is right to say that “violations of jus in bello do not affect the jus ad bellum question.”

But in the composite or compound sense of “a just war,” it must meet both conditions (as well as being pursued by a legitimate power, which is itself a complex question. Compare for instance Augustine’s question, “Set justice aside and what are kingdoms but large robber bands, and what are robber bands but little kingdoms?”).

Jordan J. Ballor

Jordan J. Ballor (Dr. theol., University of Zurich; Ph.D., Calvin Theological Seminary) is director of research at the Center for Religion, Culture & Democracy, an initiative of the First Liberty Institute. He has previously held research positions at the Acton Institute and Vrije Universiteit Amsterdam, and has authored multiple books, including a forthcoming introduction to the public theology of Abraham Kuyper. Working with Lexham Press, he served as a general editor for the 12 volume Abraham Kuyper Collected Works in Public Theology series, and his research can be found in publications including Journal of Markets & Morality, Journal of Religion, Scottish Journal of Theology, Reformation & Renaissance Review, Journal of the History of Economic Thought, Faith & Economics, and Calvin Theological Journal. He is also associate director of the Junius Institute for Digital Reformation Research at Calvin Theological Seminary and the Henry Institute for the Study of Christianity & Politics at Calvin University.